Triarylaminium Salt Induced Oxidative Cyclizations of Tertiary Amines. Convenient Access to 2-Substituted Pyrrolidinium Salts

Although they are common intermediates, the application of aliphatic tertiary aminium radical cations to organic synthesis has so far been restricted to α-deprotonation and related reactions. We report the very convenient oxidative generation and facile 5-exo cyclization of tertiary amimium radical cations to distonic 2-substituted pyrrolidinium radical cations. These can be further oxidized to 1,3-dications and trapped by nucleophiles as water, alcohols, or chloride ion. Preliminary mechanistic issues and implications will be presented.